This gas-giant exoplanet has water-rich clouds. Here's why it thrills astronomers.

rod

Oct 22, 2019
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Three teams of astronomers have been fascinated by an alien world known as K2-18b. But what's all the fuss about?

This gas-giant exoplanet has water-rich clouds. Here's why it thrills astronomers. : Read more
The report stated "Although scientists have studied exoplanet atmospheres before, those worlds have been larger than K2-18b, which is only about 2.6 times the size of Earth and 8.5 times its mass. The planet's small size made the observations especially challenging, requiring multiple detailed measurements that, combined, could provide a more in-depth probe of the world."

Using the properties for mass and size, the mean density is some 2.66 g cm^3. The eccentricity is 0.2, more like Mercury's orbit compared to the Earth :) The semi-major axis is 0.143 a.u. compared to Mercury's 0.387 a.u. This report is objective in stating, "Although K2-18b has the right conditions for Earth-like clouds to form, that doesn't make the planet itself Earth-like. Instead, it is classified as a sub-Neptune, a gas giant without a surface."

I do not think astronomers know the spin rate either compared to Earth's length of day. More details on K2-18 b properties can be found at Planet K2-18 b At present in my exoplanet studies, I find some exoplanets listed near 39 Mjup masses orbiting pulsars and terms like *planetors*. I am aware of *motaurs*, motorcycle with half-man on top. The motaurs are born to ride :) I am not sure about the *planetors*.
 

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